Attribute Points (ATTPTA) Tagged Record Extension (TRE) Specification

Transcription

1 Attribute Points (ATTPTA) Tagged ecord Extension (TE) Specification TBD/TB Listing Page # TBD/TB Description Change Log Date Location Affected Description Effectivity Log Number Effective Description Version December 2006 Initial releasable Coordination Draft Point of Contact for this DAFT: STANAG 4545 Custodian, Laura.A.Moore@nga.mil i

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3 TABLE OF CONTENTS 1 SCOPE INTODUCTION PUPOSE EFEENCES OVEVIEW OF ATTPTA GENEAL CONCEPTS ATTPTA ATTIBUTES ATTPTA HIEACHY SINGLE AND MULTIPLE IMAGE SEGMENTS USING MULTIPLE ATTPTA ASSOCIATED TES IMPLEMENTATION GUIDANCE EQUIEMENTS TEST CITEIA ATTPTA PACK CITEIA ATTPTA UNPACK CITEIA APPLICATION NOTES iii

4 1 SCOPE 1.1 Introduction The ability to provide spatial location for specific pixels in an image array has long been a desired function throughout the imagery community. There are various reasons for needing such information and the Nato Secondary Image Format (NSIF) Standard (STANAG 4545) provides several mechanisms for meeting this requirement. The Attribute Points Version A (ATTPTA) Tagged ecord Extension (TE) provides one method in which arbitrary pixels within an image array can be assigned a spatial location accompanied by other pertinent metadata such as accuracy and source history. 1.2 Purpose The purpose of this document is to define the ATTPTA TE and how it shall be used. This TE provides a mechanism for assignment of a spatial location to a row/column pixel of an image array. The name of the TE, Attribute Points TE does not imply a specific derivation of the location and therefore a source description is required along with a horizontal and vertical accuracy statement. The ATTPTA TE allows assignment of other non-spatial attributes to a pixel(s) as well. The objectives used in developing the ATTPTA were: Assign a latitude and longitude to any row/column point in an array Identify the source from which the coordinate was obtained Assign attributes to the points Apply attributes to a group of points or individual points Avoid redundancy by allowing a group of points to be defined once, but apply to one or more image segments Allow random placement of points Declare the coordinate system to which the data is geo-referenced Address how to handle the TE at different exploitation stages, e.g. chipping, editing, catalog and retrieval, etc Use existing standards and accepted methods whenever possible 2 EFEENCES NIMA STDI-0002 MIL-STD-2500B The Compendium of Controlled Extensions (CE) for the National Imagery Transmission Format, Version 2.1, 16 November 2000 National Imagery Transmission Format Version 2.1 for the National Imagery Transmission Format Standard, Notice 2, 01 March 2001 B-4

5 STANAG 7074 The Digital Geographic Information Exchange Standard (DIGEST), Edition 2.1, September OVEVIEW OF ATTPTA 3.1 General Concepts ATTPTA Attributes The ATTPTA tag can potentially consist of one or many individual points, each with its own set of attributes (see Figure 1 below). A point is defined by a row/column pixel and must be accompanied by at least one attribute. Attributes are carried in one or more conditional looping structures provided in the ATTPTA. There are four types of attributes that may be assigned to points in a group (see definition of group below): Global Constant (GCA), Global Variable (GVA), Local Constant (LCA), and Local Variable (LVA). Constant Attribute an attribute that holds a single value for all the points in a group Variable Attribute an attribute that does not have the same value for every point in a group Group one or more points and/or attributes combined, usually for purposes of optimizing repetition of attributes. There are no restrictions on forming groups. Developers are free to form groups however it best fits the needs of the program. Note: a group can consist of a single point and there may be one or more groups per TE. Global Attribute an attribute that applies to all the points in a single TE. Local Attribute an attribute that applies to all the points of a group. The ATTPTA TE allows any published library/source of attribute values. The library/source must be identified in the Attribute Source (ATT_CS) field. New libraries/sources of attributes can be registered with the STANAG 4545 Custodian by following the configuration management plan located in AEDP-4, Figure 1. Conceptual ATTPTA TE Example B-5

6 Image ATTPTA Point ow/col Lat/Lon CE/LE AHA/AVA GSD Slant ange etc Irregular grid pattern w/uneven spacing allowed but not required ATTPTA Hierarchy The basic hierarchy of ATTPTA is as follows: List of which image segment(s) the TE apply to List of Global Constant Attributes and their values List of Global Variable Attributes For each group (one or many): List of Local Constant Attributes and their values List of Local Variable Attributes For each point (one or many): ow Column Global Variable Attribute value(s) Local Variable Attribute value(s) Single and Multiple Image Segments The ATTPTA TE can apply to one or more NSIF Image (IM) Segments. If the TE applies to a single IM segment, the ATTPTA must be present in that IM subheader or in a corresponding TE Overflow Data Extension Segment (DES). If the ATTPTA applies to more than one IM Segment, it must be present in the NSIF Main Header or TE Overflow DES from the Main Header or repeated in each individual image segment subheader that the data applies to Using Multiple ATTPTA There can be multiple ATTPTA TEs in a single NSIF segment or file. Organization of the attribute points is an implementation decision. This specification does not limit the number of points that can be recorded in a single TE other than the standard B-6

7 TE size limit of It is feasible to write a TE for every point, write one TE containing all the points or have multiple TEs with multiple points Associated TEs When using the ATTPTA TE the Geo positioning Information TE (GEOPSB) must also be present (see DIGEST Part 2 Annex D, Appendix D1). GEOPSB provides geo-referencing parameters including coordinate system type, datum and ellipsoid Implementation Guidance Due to the ATTPTA s general purpose nature and flexibility, it is highly recommended that programs interested in using this TE prepare an implementation specification detailing the attributes and type of attributes (global, local, constant variable) their program will be using. 4 EQUIEMENTS The following table defines the format of the ATTPTA TE. Table 1. ATTPTA Attribute Points = equired, C = Conditional, A = Alphanumeric, N = Numeric, <> = Designated Default Value Allowed Field Name/Description Size Value ange Units Type CETAG Unique Extension Identifier The last character identifies the version of the TE A/6 BCS-A ATTPTA CEL Length of data to follow This field shall contain the length in bytes of the data in the ATTPTA TE that follows. N/5 BCS-N positive 244 CEL IMC Image Segment Count This field contains the number of image segments this TE applies to. All image segments must be present in this NSIF file. N/3 BCS-N positive B-7

8 Table 1. ATTPTA Attribute Points = equired, C = Conditional, A = Alphanumeric, N = Numeric, <> = Designated Default Value Allowed Field Name/Description Size Value ange Units Type ATT_CS ID_TYPE IMIDn Attribute Code Source This field provides the published library/source in which the attribute codes used in this TE are defined. New libraries/sources of attributes can be registered with the STANAG 4545 Custodian by following the configuration management plan located in AEDP-4, Note: Each ATTPTA TE can only contain attributes from a single source. Multiple ATTPTA TE shall be used when attributes have different sources. Type of Image Identification This field identifies the type of identification provided in the IMIDn field. In most cases, where a unique NSIF image identifier 2 (IID2) field is present, the IMIDn value will match the IID2 from the relevant image segment subheader, in which case this field shall contain a 1. When, and only when a unique IID2 field is not available, the IMIDn shall be populated with the Display Level (DL) from the relevant image segment subheader, in which case this field shall contain a 2. A/40 BCS-A N/1 BCS-N 1 or 2 Start for each image segment (IMID repeats IMC times) Image Segment Identification This field contains the image identification of the nth image segment that this TE applies to. In most cases, where a unique NSIF image identifier 2 (IID2) field is present, the IMIDn value will match the IID2 from the relevant image segment subheader. When, and only when a unique IID2 field is not present, this field shall be populated with the Display Level (DL) from the relevant image segment subheader in the format DLXXX, where XXX is equal to the display level. End for each image segment A/80 BCS-A B-8

9 Table 1. ATTPTA Attribute Points = equired, C = Conditional, A = Alphanumeric, N = Numeric, <> = Designated Default Value Allowed Field Name/Description Size Value ange Units Type NUMGCA Number of Global Constant Attributes This field shall contain the number of constant attribute values that apply to all the attribute points in this TE. If this field is 000, ATT_IDn through ATT_UNITSn (immediately below) will not be present. N/3 BCS-N positive Start for each global constant attribute (ATT_IDn through ATT_UNITSn repeats NUMGCA times) ATT_IDn ATT_LENn ATT_VALUEn ATT_UNITSn Attribute Identification NUMGCA > 0 and will provide the name of the nth GCA. Allowed attributes are from the library/source indicated in the ATT_SC field above. New attributes can be registered through the STANAG 4545 Custodian. Attribute Length NUMGCA > 0 and will provide the length of the ATT_VALUEn field immediately below. Attribute Value NUMGCA > 0 and will provide the nth GCA value. Allowed attributes are from the library/source indicated in the ATT_SC field above. New attributes can be registered through the STANAG 4545 Custodian. *The ATT_LENn field defines the length of this field. Attribute Unit of Measure NUMGCA > 0 and will provide the unit of measure associated with the nth GCA. Standard values are from DIGEST Part 3-7. If no unit of measure is applicable, the default is hyphens "----". Note: Codes enclosed in parentheses indicate non- ISO 1000 units. The parentheses themselves do not form part of the code. A/6 BCS-A C N/4 BCS-N positive Bytes A/* BCS-A C A/4 BCS-A ---- or values from DIGEST Part 3-7 C <C> B-9

10 Table 1. ATTPTA Attribute Points = equired, C = Conditional, A = Alphanumeric, N = Numeric, <> = Designated Default Value Allowed Field Name/Description Size Value ange Units Type ASn NUMGVA Attribute Source NUMGCA > 0 and will provide a description of the original source of the attribute in citation form, no codes. End for each global constant attribute Number of Global Variable Attributes This field shall contain the number of variable attributes that apply to all the attribute points in this TE. The values for these attributes will immediately follow the attribution point (see GVAn field below). If this field is 000, ATT_IDn through ATT_UNITSn (immediately below) will not be present. A/40 BCS-A C N/3 BCS-N positive Start for each global variable attribute (ATT_ID through ATT_UNITS repeats NUMGVA times) ATT_IDn ATT_LENn ATT_UNITSn Attribute Identification NUMGVA > 0 and will provide the name of the nth GVA. Allowed attributes are from the library/source indicated in the ATT_SC field above. New attributes can be registered through the STANAG 4545 Custodian. Attribute Length NUMGVA > 0 and will provide the length of the nth GVA. Actual GVA values are provided in the attribute point loop below. Attribute Unit of Measure NUMGVA > 0 and will provide the unit of measure associated with the nth GVA. Standard values are from DIGEST Part 3-7. If no unit of measure is applicable, the default is hyphens "----". Note: Codes enclosed in parentheses indicate non- ISO 1000 units. The parentheses themselves do not form part of the code. A/6 BCS-A C N/4 BCS-N positive A/4 BCS-A ---- or values from DIGEST Part 3-7 Bytes C <C> B-10

11 Table 1. ATTPTA Attribute Points = equired, C = Conditional, A = Alphanumeric, N = Numeric, <> = Designated Default Value Allowed Field Name/Description Size Value ange Units Type ASn NUMG NUMLCAn Attribute Source NUMGVA > 0 and will provide a description of the original source of the attribute in citation form, no codes. End for each global variable attribute Number of Groups This field shall contain the number of groups that this TE is separated into. A/40 BCS-A C N/3 BCS-N positive Start for each group (repeats NUMG times) Number of Local Constant Attributes in the nth Group N/3 BCS-N positive Start for each Local Constant attribute in the nth group (ATT_ID through ATT_UNITS repeats NUMLCA times) ATT_IDn ATT_LENn ATT_VALUEn Attribute Identification NUMLCAn > 0 and will provide the name of the nth LCA. Allowed attributes are from the library/source indicated in the ATT_SC field above. New attributes can be registered through the STANAG 4545 Custodian. Attribute Length NUMLCA > 0 and will provide the length of the ATT_VALUEn field immediately below. Attribute Value NUMGCA > 0 and will provide the nth LCA value. Allowed attributes are from the library/source indicated in the ATT_SC field above. New attributes can be registered through the STANAG 4545 Custodian. *The ATT_LENn field defines the length of this field. A/6 BCS-A C N/4 BCS-N positive Bytes A/* BCS-A C C B-11

12 Table 1. ATTPTA Attribute Points = equired, C = Conditional, A = Alphanumeric, N = Numeric, <> = Designated Default Value Allowed Field Name/Description Size Value ange Units Type ATT_UNITSn ASn NUMLVA Attribute Unit of Measure NUMLCA > 0 and will provide the unit of measure associated with the nth LCA. Standard values are from DIGEST Part 3-7. If no unit of measure is applicable, the default is hyphens "----". Note: Codes enclosed in parentheses indicate non- ISO 1000 units. The parentheses themselves do not form part of the code. Attribute Source NUMLCA > 0 and will provide a description of the original source of the attribute in citation form, no codes. A/4 BCS-A ---- or values from DIGEST Part 3-7 <C> A/40 BCS-A C End for each Local Constant attribute in the nth group Number of Local Variable Attributes in the nth Group The values for these attributes will immediately follow the global variable attributes (see LVAn field below). N/3 BCS-N positive Start for each Local Variable attribute (ATT_ID through ATT_UNITS repeats NUMLVA times) ATT_IDn ATT_LENn Attribute Identification NUMLVA > 0 and will provide the name of the nth LVA. Allowed attributes are from the library/source indicated in the ATT_SC field above. New attributes can be registered through the STANAG 4545 Custodian. Attribute Length NUMLVA > 0 and will provide the length of the nth LVA. Actual LVA values are provided in the attribute point loop below. A/6 BCS-A C N/4 BCS-N positive Bytes C B-12

13 Table 1. ATTPTA Attribute Points = equired, C = Conditional, A = Alphanumeric, N = Numeric, <> = Designated Default Value Allowed Field Name/Description Size Value ange Units Type ATT_UNITSn ASn NUM_PTS DIY DIX GVAn GVAn+1 LVAn LVAn+1 Attribute Unit of Measure NUMLVA > 0 and will provide the unit of measure associated with the nth LVA. Standard values are from DIGEST Part 3-7. If no unit of measure is applicable, the default is hyphens "----". Note: Codes enclosed in parentheses indicate non- ISO 1000 units. The parentheses themselves do not form part of the code. Attribute Source NUMLVA > 0 and will provide a description of the original source of the attribute in citation form, no codes. A/4 BCS-A ---- or values from DIGEST Part 3-7 End for each Local Variable attribute in the nth group Number of Attribute Points in the nth Group The number of points can not cause the CEL to exceed <C> A/40 BCS-A C N/4 BCS-N positive Start for each attribute point in the nth group (repeats NUM_PTS times) ow Number of Attribute Point This field shall contain the row number of the corresponding pixel. Column Number of Attribute Point This field shall contain the column number of the corresponding pixel. Global Variable Attribute Value n NUMGVA is > 0. Local Variable Attribute Value n NUMLVA is > 0. End for each attribute point End for each group N/8 BCS-N N/8 BCS-N See relevant GVAn or LVAn ATT_ID through ATT_UNITS for definition of each attribute C B-13

14 5 TEST CITEIA 5.1 ATTPTA Pack Criteria The following test criteria apply to the packing (generation) of NSIF files when using the ATTPTA TE All character values in ATTPTA TE are in the printable BCS-A character set (space (0x20) through tilde (0x7E)) with eight bits (one byte per character) All data in fields designated as alphanumeric (BCS-A) are left justified and padded with spaces as necessary to fill the field All data in numeric (BCS-N) fields are right justified and padded with leading zeros as necessary to fill the field All required fields are present and contain valid data as defined in the ATTPTA specification Each point must have at least one attribute Conditional fields are only present when the conditional parameters of predicate fields so signify. When present, conditional fields contain valid data Fields are not populated with default or unknown-designator values unless the actual value is truly unavailable at the specific lifecycle stage of data formation If there are more attribute points than would fit in a single TE, multiple TEs can be used, or every attribute point could be placed in its own TE Any portion of a coordinate that is unknown shall be filled with a hyphen (-), including a completely unknown coordinate (e.g ). The default hyphen convention should only be used under special circumstances such as when the coordinate will for sure be known at a later date and populated in full ecommend producers of the ATTPTA TE define the records starting from the upper left corner of the image or image segment one record at a time until the lower right corner is reached. The record placement can be variable with regard to pixel spacing in the column and row direction. 5.2 ATTPTA Unpack Criteria The ATTPTA TE specification does not define specific functional requirements for unpack, interpretation and use of the information. Therefore, the following unpack test criteria serve as foundation principles for determining compliance for whatever ATTPTA-based functionality a specific implementation supports. These criteria B-14

15 serve as the basis for establishing the appropriate compliance test measures for the specified functional requirements of the IUT An exploitation system must be able to apply the attribute points to obtain better geographic locations across the image than the IGEOLO corner points would provide An exploitation system must be able to make the attributes of a point available to the operator. 6 APPLICATION NOTES Candidate Topics for Inclusion in APPLICATION NOTES section: Sample implementations of the TE. B-15